Shielded package having shield lid

ABSTRACT

A shielded package includes a shield assembly having a shield fence, a shield lid, and a shield lid adhesive electrically coupling the shield lid to the shield fence. The shield fence includes a porous sidewall through which molding compound passes during molding of the shielded package. Further, the shield fence includes a central aperture through which an electronic component is die attached and wire bonded.

RELATED APPLICATIONS

This application is a continuation of Foster, U.S. patent applicationSer. No. 10/992,036, filed on Nov. 17, 2004, now U.S. Pat. No. 7,629,674which is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the packaging of electroniccomponents. More particularly, the present invention relates to ashielded electronic component package and method of fabricating thesame.

2. Description of the Related Art

As the art moved to smaller, lighter weight, and higher frequency electronic devices such as cellular telephones, integrated circuitpackages utilized in these electronic devices were increasingly placedcloser to other electronic components and structures. Due to thisreduced spacing, radiation such as electromagnetic or radio frequency(RF) radiation emanating from an integrated circuit package had agreater probability of interfering with the normal operation of anadjacent electronic component and vice versa. However, such interferencewas unacceptable depending upon the particular application.

Further, to prevent interfering with the normal operation of adjacentelectronic devices, e.g., radio receivers, it was important to preventthe integrated circuit package from emanating unwanted radiation to theambient air. Similarly, to prevent interfering with the normal operationof the integrated circuit package, it was important to protect theelectronic component(s) of the integrated circuit package from radiationemanating from adjacent electronic devices, e.g., radio transmitters.Stated generally, it was important to prevent unwanted radiation fromelectronic component(s) of the integrated circuit package from reachingthe surrounding air and vice versa.

To prevent unacceptable electromagnetic interference, a shielding systemwas used. Typically, an electrically conductive metallic enclosure wasplaced around the integrated circuit package after the integratedcircuit package was mounted to the larger substrate such as the printedcircuit mother board. However, fabricating such a metallic enclosure andseparately attaching the metallic enclosure to the printed circuitmother board was relatively cumbersome, complex, and costly.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a shieldedpackage includes a shield assembly having a shield fence, a shield lid,and a shield lid adhesive electrically coupling the shield lid to theshield fence. The shield fence includes a porous sidewall through whichmolding compound passes during molding of the shielded package. Further,the shield fence includes a central aperture through which an electroniccomponent is die attached and wire bonded.

In accordance with another embodiment, the shield assembly of theshielded package includes the shield fence and an electricallyconductive ink electrically coupled to the shield fence.

These and other features of the present invention will be more readilyapparent from the detailed description set forth below taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a shielded package 100 inaccordance with one embodiment of the present invention;

FIG. 2 is a cross-sectional view of the shielded package along the lineII-II of FIG. 1;

FIG. 3 is an enlarged perspective view of a region III of a shield fenceof the shielded package of FIG. 1;

FIG. 4 is a cross-sectional view of a shielded package in accordancewith another embodiment of the present invention;

FIG. 5 is a cross-sectional view of an assembly during the fabricationof a plurality of shielded packages in accordance with one embodiment ofthe present invention;

FIGS. 6, 7 and 8 are cross-sectional views of the assembly of FIG. 5 atfurther stages of fabrication;

FIG. 9 is a cross-sectional view of the assembly of FIG. 7 at a furtherstage of fabrication in accordance with another embodiment of thepresent invention; and

FIG. 10 is a cross-sectional view of a shielded package in accordancewith another embodiment of the present invention.

In the following description, the same or similar elements are labeledwith the same or similar reference numbers.

DETAILED DESCRIPTION

Referring to FIG. 1, a shielded package 100 includes a shield assembly140 having a shield fence 142, a shield lid 144, and a shield lidadhesive 146 electrically coupling shield lid 144 to shield fence 142.Shield fence 142 includes molding apertures 170 through which moldingcompound passes during molding of shielded package 100. Further, shieldfence 142 includes a central aperture 157 through which an electroniccomponent 104 is die attached and wire bonded to a substrate 102.

More particularly, FIG. 1 is an exploded perspective view of a shieldedpackage 100 in accordance with one embodiment of the present invention.FIG. 2 is a cross-sectional view of shielded package 100 along the lineII-II of FIG. 1.

Referring now to FIGS. 1 and 2 together, shielded package 100 includes asubstrate 102 such as a printed circuit board, ceramic or tape althoughother materials are used in other embodiments. Substrate 102 includes anupper, e.g., first, surface 102U and a lower, e.g., second, surface102L.

An electronic component 104 such as an integrated circuit is mounted toupper surface 102U with, for example, adhesive 106. More particularly, arear, e.g., first, surface 104R of electronic component 104 is mountedto upper surface 102U of substrate 102 by adhesive 106.

A front, e.g., second, surface 104F of electronic component 104 hasformed thereon bond pads 108 including a first bond pad 108A. Bond pads108 are electrically connected to the various internal circuitry ofelectronic component 104 (not shown).

Formed on upper surface 102U of substrate 102 are a plurality ofelectrically conductive upper traces 110 including a first upper trace110A. Bond pads 108 are electrically connected to upper traces 110 byelectrically conductive bond wires 112. To illustrate, bond pad 108A iselectrically connected to upper trace 110A by a first bond wire 112A ofthe plurality of bond wires 112. The other bond pads 108 areelectrically connected to the other upper traces 110 by the other bondwires 112 in a similar manner so are not discussed further to avoiddetracting from the principles of the invention.

Formed on lower surface 102L of substrate 102 are a plurality ofelectrically conductive lower traces 114 including a first lower trace114A. Upper traces 110 are electrically connected to lower traces 114 byelectrically conductive vias 116 extending through substrate 102 fromupper surface 102U to lower surface 102L.

To illustrate, upper trace 110A is electrically connected to lower trace114A by a first via 116A of the plurality of vias 116. The other uppertraces 110 are electrically connected to the other lower traces 114 bythe other vias 116 in a similar manner so are not discussed further toavoid detracting from the principles of the invention.

Formed on lower traces 114 are electrically conductive pads 118. Toillustrate, a first pad 118A of the plurality of pads 118 is formed onand electrically connected to lower trace 114A. Formed on andelectrically connected to pads 118 are electrically conductiveinterconnection balls 120, e.g., solder. To illustrate, a firstinterconnection ball 120A of the plurality of interconnection balls 120is formed on and electrically connected to pad 118A.

As set forth above, an electrically conductive pathway between bond pad108A and interconnection ball 120A is formed by bond wire 112A, uppertrace 110A, via 116A, lower trace 114A and pad 118A. The other bond pads108, bond wires 112, upper traces 110, vias 116, lower traces 114, pads118 and interconnection balls 120 are electrically connected to oneanother in a similar fashion so are not discussed further to avoiddetracting from the principles of the invention.

Also formed on upper surface 102U of substrate 102 is an electricallyconductive ground ring 122. In accordance with this embodiment, groundring 122 is a rectangular annulus around the entire periphery of uppersurface 102U. In another embodiment, instead of being a single integralconductor, ground ring 122 is formed from a plurality of conductors,e.g., lands.

Formed on lower surface 102L of substrate 102 are electricallyconductive lower ground traces 124 including a first lower ground trace124A. Ground ring 122 is electrically connected to lower ground traces124 by electrically conductive ground vias 126 extending throughsubstrate 102 from upper surface 102U to lower surface 102L. Toillustrate, ground ring 122 is electrically connected to lower groundtrace 124A by a first ground via 126A of the plurality of ground vias126.

Formed on lower ground traces 124 are electrically conductive groundpads 128. To illustrate, a first ground pad 128A of the plurality ofground pads 128 is formed on and electrically connected to lower groundtrace 124A. Formed on and electrically connected to ground pads 128 areelectrically conductive ground interconnection balls 130, e.g., solder.To illustrate, a first ground interconnection ball 130A of the pluralityof ground interconnection balls 130 is formed on ground pad 128A.

As set forth above, an electrically conductive pathway between groundring 122 and ground interconnection ball 130A is formed by ground via126A, lower ground trace 124A and ground pad 128A. Generally, shieldedpackage 100 includes at least one ground via 126, lower ground trace124, ground pad 128 and ground interconnection ball 130. The otherground vias 126, lower ground traces 124, ground pads 128 and groundinterconnection balls 130, if any, are electrically connected to oneanother and ground ring 122 in a similar fashion so are not discussedfurther to avoid detracting from the principles of the invention.

Although particular electrically conductive pathways between bond pads108, ground ring 122 and interconnection balls 120, groundinterconnection balls 130, respectively, are described above, in lightof this disclosure, it is understood that other electrically conductivepathways can be formed. For example, substrate 102 is a multi-layeredlaminate substrate and, instead of straight-through vias 116, 126, aplurality of electrically conductive traces on various layers insubstrate 102 are interconnected by a plurality of electricallyconductive vias to form the electrical interconnections between uppertraces 110, ground ring 122 and traces 114, 124, respectively.

In one embodiment, interconnection balls 120, 130 are distributed in anarray format to form a ball grid array (BGA) package. Alternatively,interconnection balls 120, 130 are not formed, e.g., to form a metalland grid array (LGA) package or a leadless chip carrier (LCC) package.In another alternative, pads 118, 128 are not formed and interconnectionballs 120, 130 are formed directly on lower traces 114, 124,respectively. Further, contact metallizations are interposed between thevarious conductors in other embodiments. Other electrically conductivepathway modifications will be obvious to those of skill in the art.

In one embodiment, dielectric layers (not shown), e.g., solder masks,cover and protect portions of upper traces 110, lower traces 114, lowerground traces 124 and/or ground ring 122.

Shielded package 100 further includes a shield assembly 140. In thisembodiment, shield assembly 140 includes a shield fence 142, a shieldlid 144, and a shield lid adhesive 146. Illustratively, shield fence 142and shield lid 144 are formed of an electrically conductive material ormaterials, e.g., stainless steel, copper, or other electricallyconductive material. For example, an electrically conductive material isstamped, etched or otherwise shaped to form shield fence 142 and shieldlid 144.

FIG. 3 is an enlarged perspective view of a region III of shield fence142 of shielded package 100 of FIG. 1. Referring now to FIGS. 1, 2, and3 together, shield fence 142 includes a shield lid mounting ring 150,posts 152, and post supports 154. Posts 152 are sometimes called legs orfingers.

Shield lid mounting ring 150 is a rectangular annulus and includes aninner periphery 156 and an outer periphery 158. Inner periphery 156defines a central aperture 157 of shield lid mounting ring 150 and moregenerally of shield fence 142.

Shield lid mounting ring 150 further includes a shield lid mountingsurface 160. Shield lid mounting surface 160 is parallel to uppersurface 102U of substrate 102, e.g., lies in a horizontal plane. Moregenerally, shield lid mounting ring 150 is parallel to upper surface102U of substrate 102.

Extending from outer periphery 158 of shield lid mounting ring 150 areposts 152. Posts 152 included first, e.g., upper, ends 162 and second,e.g., lower, ends 164.

Posts 152 are perpendicular to shield lid mounting ring 150, e.g., liein vertical planes. Upper ends 162 of posts 152 are bends extendingdownwards from shield lid mounting ring 150. Accordingly, posts 152extend downwards from shield lid mounting ring 150 and towards substrate102. Posts 152 are shaped as rectangular posts in accordance with thisembodiment.

Lower ends 164 of posts 152 are surfaces parallel to upper surface 102Uof substrate 102. Lower ends 164 of posts 152 collectively define ashield connection surface 166 of shield fence 142 and generally ofshield assembly 140 as indicated by the dashed line.

Shield connection surface 166 of shield fence 142 corresponds in shapeto ground ring 122, e.g., shield connection surface 166 and ground ring122 are both rectangular annuli of approximately the same dimension.More particularly, when shield assembly 140 is mounted to substrate 102,shield connection surface 166 of shield fence 142 abuts ground ring 122as best shown in FIG. 2. This allows shield fence 142 and more generallyshield assembly 140 to be electrically connected to ground ring 122.

In one embodiment, shield fence 142 and more specifically shieldconnection surface 166 is mounted and electrically connected to groundring 122 by electrically conductive ground ring adhesive 168.Illustratively, electrically conductive ground ring adhesive 168 is anelectrically conductive epoxy adhesive or solder although otherelectrically conductive adhesives are used in other embodiments. Groundring adhesive 168 is not illustrated in FIGS. 1 and 3 for purposes ofclarity.

Post supports 154 extend between and connected adjacent posts 152, e.g.,extend in the horizontal direction. Post supports 154 support posts 152and generally provide rigidity and strength to shield fence 142 in oneembodiment.

To illustrate, a first post support 154A of the plurality of postsupports 154 extend horizontally between a first post 152A of theplurality of posts 152 and a second post 152B of the plurality of posts152.

Posts 152 and post supports 154 define molding apertures 170. Generally,posts 152 and post supports 154 form a porous sidewall 153, sometimescalled a porous opening sidewall, of shield fence 142.

As set forth further below, molding compound passes through moldingapertures 170 to enclose electronic component 104 and any otherelectronic components mounted to upper surface 102U, bond wires 112,upper surface 102U of substrate 102, posts 152, and post supports 154.

Further, as those of skill in the art will understand, by formingmolding apertures 170 with a sufficiently small area, radiation isprevented from passing through molding apertures 170. Generally, themaximum allowable area of molding apertures 170 to prevent emissions,e.g., RF emissions, is determined by the operating frequency(ies) ofelectronic components of shielded package 100.

Molding apertures 170 include upper, e.g., first, molding apertures 172and lower, e.g., second, molding apertures 174 in accordance with thisembodiment. Generally, shield lid mounting ring 150, posts 152, postsupports 154, and posts 152 define upper molding apertures 172. Further,posts 152 and post supports 154 define lower molding apertures 174.

To illustrate, shield lid mounting ring 150, post 152A, post support154A, and post 152B define a first upper molding aperture 172A of theplurality of upper molding apertures 172. To further illustrate, post152A, post 152B and post support 154A define a first lower moldingaperture 174A of the plurality of lower molding apertures 174. The otherupper molding apertures 172 and lower molding apertures 174 are definedin a similar manner and so are not discuss further to avoid detractingfrom the principles of invention.

In accordance with one embodiment, post supports 154 are optional andare not formed. In accordance with this embodiment, molding apertures170 are define by shield lid mounting ring 150 and posts 152.

Shield lid 144 is a planar lid corresponding closely in shape to outerperiphery 158 of shield lid mounting ring 150 of shield fence 142.Shield lid 144 is mounted and electrically coupled to shield lidmounting ring 150 of shield fence 142 by shield lid adhesive 146. Moreparticularly, shield lid 144 is mounted and electrically coupled toshield lid mounting surface 160 of shield lid mounting ring 150 byshield lid adhesive 146.

Illustratively, shield lid adhesive 146 is an electrically conductiveepoxy adhesive or solder although other electrically conductiveadhesives are used in other embodiments. Shield lid adhesive 146 is notillustrated in FIG. 3 for purposes of clarity.

As shown in FIG. 2, electronic component 104 including bond wires 112are protected by an encapsulant 176, sometimes called molding compoundor a mold cap. For simplicity, encapsulant 176 is not illustrated inFIGS. 1 and 3.

More generally, encapsulant 176 encloses upper surface 102U of substrate102 including any structures thereon, e.g., ground ring 122, uppertraces 110, bond wires 112, electronic component 104. Further,encapsulant 176 encloses shield fence 142 including ground ring adhesive168.

Encapsulant 176 includes an upper surface 176U parallel to and in thesame plane as shield lid mounting surface 160 of shield lid mountingring 150 of shield fence 142. Generally, shield lid mounting surface 160is uncovered by encapsulant 176 and exposed facilitating mounting ofshield lid 144 by shield lid adhesive 146 to shield lid mounting surface160.

A lower, e.g., first, surface 144L of shield lid 144 is directlyadjacent to upper surface 176U of encapsulant 176. In accordance withthis embodiment, shield lid 144 is slightly spaced above encapsulant 176by shield lid adhesive 146. However, in other embodiment, shield lid 144is in abutting contact with upper surface 176U of encapsulant 176.

As best shown in FIG. 1, ground ring 122 defines a central region CR ofupper surface 102U of substrate 102 inwards of ground ring 122. Theelectronic components of shielded package 100 are mounted to centralregion CR. To illustrate, electronic component 104 and a secondelectronic component 178 are mounted to central region CR, i.e., for atotal of two electronic components. However, in alternative embodiments,more or less than two electronic components are mounted to centralregion CR.

Further, instead of being mounted to upper surface 102U of substrate102, electronic components 104 and/or 178 are embedded within substrate102 below central region CR in one embodiment. For example, substrate102 is a multilayer substrate, e.g., a multilayer laminate substrate,and electronic components 104 and/or 178 are formed on an interlayer ofsubstrate 102.

Illustratively, electronic components 104 and 178 are semiconductordevices, discrete passive devices such as resistors, capacitors orinductors, discrete active devices, application-specific integratedcircuits (ASICs), integrated passive networks or combinations thereofalthough other electronic components are used in other embodiments.

Shield assembly 140 functions as a shield to protect electroniccomponents 104 and 178 from radiation. Examples of radiation of interestinclude electromagnetic radiation or radio frequency (RF) radiation.Stated another way, shield assembly 140 shields electronic components104 and 178 from interference such as electromagnetic interference (EMI)or radio frequency interference (RFI). Further, shield assembly 140functions as a shield to prevent electronic components 104 and 178 fromemanating unwanted radiation to electronic components, structures,and/or air adjacent shielded package 100.

As set forth above, shield assembly 140 is formed of an electricallyconductive material and is electrically connected to ground ring 122.More generally, shield assembly 140 is physically and electricallyconnected to ground ring 122.

As set forth above, ground ring 122 is electrically connected to groundinterconnection balls 130. Accordingly, shield assembly 140 iselectrically connected to ground interconnection balls 130.

During use, ground interconnection balls 130 are electrically connectedto a reference voltage source, e.g., ground. Accordingly, shieldassembly 140 is electrically connected to the reference voltage sourceand held at a common potential, e.g., ground. Thus, shield assembly 140is a ground shield that encloses electronic components 104 and 178. Moreparticularly, shield lid 144 of shield assembly 140 is a ground shieldabove electronic components 104 and 178. Shield fence 142 of shieldassembly 140 is a ground shield around electronic components 104 and178.

Further, ground vias 126 collectively form a ground shield around theentire periphery and adjacent side 102S of substrate 102, this groundshield extending from upper surface 102U to lower surface 102L ofsubstrate 102. Ground vias 126 are grounded by ground interconnectionballs 130 for reasons similar to those set forth above regarding shieldassembly 140. As those of skill in the art will understand, by spacingground vias 126 sufficiently close to one another, radiation isprevented from passing between ground vias 126. Accordingly, ground vias126 prevent lateral transmission of radiation through side 102S ofsubstrate 102. In this manner, ground vias 126 form a ground shieldbelow and beside electronic components 104 and 178.

In one embodiment, substrate 102 and/or the larger substrate, e.g. theprinted circuit mother board, to which shielded package 100 is mounted,is formed with a ground plane. For example, substrate 102 includes aground plane 180 electrically coupled to one or more of ground vias 126as shown in FIG. 2. Ground plane 180 prevents radiation from passingthrough substrate 102. As a result, electronic components 104 and 178are completely shielded from radiation in all directions. Further,electronic components, structures and/or air adjacent shielded package100 are shielded from radiation emanating from electronic components 104and 178.

FIG. 4 is a cross-sectional view of a shielded package 400 in accordancewith another embodiment of the present invention. Shielded package 400of FIG. 4 is substantially similar to shielded package 100 of FIG. 2 andonly the significant differences are discussed below.

Referring now to FIG. 4, in this embodiment, electronic component 104 isflip chip mounted to substrate 102. More particularly, electroniccomponent 104 is mounted to substrate 102 by bumps 412 including a firstbump 412A. Bumps 412 physically and electrically connect bond pads 108to upper traces 110. To illustrate, bump 412A physically andelectrically connects bond pad 108A to upper trace 110A.

In this embodiment, to insure the reliability of the mounting ofelectronic component 104 to substrate 102, an underfill material 440 isapplied to enclose bumps 412 and generally to fill the space betweenfront surface 104F of electronic component 104 and upper surface 102U ofsubstrate 102.

FIG. 5 is a cross-sectional view of an assembly 500 during thefabrication of a plurality of shielded packages 100 in accordance withone embodiment of the present invention. Referring now to FIG. 5, anarray substrate 502 includes a plurality of individual substrates 102integrally connected together. Substrates 102 are delineated from oneanother by singulation streets 504.

Solder paste 506 is applied, e.g., by screen printing, on ground rings122, e.g., around the entire ground rings 122 or on portions of groundrings 122 corresponding to posts 152. Solder paste 506 is also appliedto selected ones of upper traces 110. In accordance with one embodiment,solder flux is applied before solder paste 506 although application ofsolder flux is optional.

Electronic components 178, e.g., passive components, are placed onsolder paste 506 on upper traces 110. Electronic components 178 aresometimes called surface mount components. Shield fences 142 are alsoplaced on solder paste 506 on ground rings 122.

In accordance with one embodiment, electronic components 178 are placedfirst and then shield fences 142 are placed second on solder paste 506.This facilitates placement of electronic components 178 as close aspossible to shield fences 142 without interference from overhangingshield lid mounting rings 150 of shield fences 142.

Assembly 500 is heated to reflow solder paste 506 and mount electroniccomponents 178 and shield fences 142 to substrates 102. Optionally,assembly 500 is flux clean to remove any flux residue from the reflowoperation.

In the above manner, shield fences 142 are attached using a surfacemount attach method, e.g. by soldering at the same time as surfacemounting of electronic components 172 reducing the number of operationscompared to mounting shield fences 142 separately from electroniccomponents 172.

FIG. 6 is a cross-sectional view of assembly 500 of FIG. 5 at a furtherstage of fabrication. Referring now to FIG. 6, rear surfaces 104R ofelectronic components 104 are mounted, sometimes called die attached, toupper surfaces 102U of substrates 102, e.g., with adhesives 106,sometimes called die attach adhesives. Bond pads 108 are electricallyconnected to upper traces 110 by bond wires 112. Optionally, uppersurfaces 102U of substrates 102 are plasma cleaned to enhance theadhesion of molding compound discussed below.

The open top design of shield fences 142 facilitates die attachment andwire bonding of electronic components 104 and plasma cleaning of uppersurfaces 102U of substrates 102. Generally, adhesives 106 and electroniccomponents 104 are mounted to upper surfaces 102U of substrates 102through central apertures 157 of shield fences 142. Further, bond pads108 are wire bonded to upper traces 110 by a wire bonder passing throughcentral apertures 157 of shield fences 142.

Although a wirebonding configuration of electronic component 104 isillustrated in FIG. 6, it is understood that other configurations, e.g.,a flip chip configuration such as that illustrated in FIG. 4, are usedin other embodiments. Generally, electronic components such aselectronic components 104 and 178 of FIG. 1 are mounted, e.g., in wirebond, flip chip, or surface mount configurations, to central regions CRof upper surfaces 102U of substrates 102. The particular method used tomount these electronic components is not essential to this embodiment ofthe present invention.

FIG. 7 is a cross-sectional view of assembly 500 of FIG. 6 at a furtherstage of fabrication in accordance with one embodiment of the presentinvention. Referring now to FIG. 7, assembly 500 is placed within a mold702. In accordance with this embodiment, mold 702 includes an upper,e.g., first, mold half 704 and a lower, e.g., second mold half 706.Lower surfaces 102L of substrates 102 are in abutting contact with lowermold half 706. Shield lid mounting surfaces 160 of shield fences 142 arein abutting contact with upper mold half 704. In this manner,overmolding of shield lid mounting surfaces 160 is prevented.

Molding compound 710 is injected into mold 702. More particularly,molding compound 710 is injected into the cavity between upper surfaces102U of substrates 102 and upper mold half 704. Molding compound 710passes through molding apertures 170 of shield fences 142 to encloseelectronic components 104, 178, bond wires 112, upper traces 110, groundrings 122, shield lid adhesives 146, and shield fences 142. As discussedabove, molding compound 710 leaves uncovered and does not enclose shieldlid mounting surfaces 160. After singulation, molding compound 710 formsencapsulants 176 for each individual shielded package 100.

In the event that molding compound 710 leaks between shield lid mountingsurfaces 160 and upper mold half 704, i.e., flash is formed on shieldlid mounting surfaces 160, a deflash process is used to remove moldingcompound 710 from shield lid mounting surfaces 160. Illustratively, alaser deflash process using UV or YAG laser is used. Assembly 500 isremoved from mold 702.

FIG. 8 is a cross-sectional view of assembly 500 of FIG. 7 at a furtherstage of fabrication in accordance with one embodiment of the presentinvention. Referring now to FIG. 8, shield lid adhesives 146 are appliedto shield lid mounting surfaces 160. Shield lids 144 are placed intoshield lid adhesives 146. Shield lid adhesives 146 are cured thusmounting and electrically coupling shield lids 144 to shield lidmounting surfaces 160.

In one embodiment, a surface mount process is used to mount shield lids144 to shield lid mounting surfaces 160. In accordance with thisembodiment, solder paste is applied, e.g., by stencil printing, toshield lid mounting surfaces 160. Shield lids 144 are placed andassembly 500 is heated to reflow the solder paste. Optionally, flux isused before the reflow operation and/or assembly 500 is cleaned afterthe reflow operation. Accordingly, shield lid adhesives 146 are solderin accordance with this embodiment.

In another embodiment, shield lid adhesives 146 are an electricallyconductive epoxy adhesive. In accordance with this embodiment, theelectrically conductive epoxy adhesive is applied, for example, with aneedle dispenser to shield lid mounting surfaces 160. Shield lids 144are placed and the electrically conductive epoxy adhesive is cured.

FIG. 9 is a cross-sectional view of assembly 500 of FIG. 7 at a furtherstage of fabrication in accordance with another embodiment of thepresent invention. Referring now to FIG. 9, an electrically conductiveink 902, sometimes called a shield lid, is formed on selected portionsof an upper surface 710U of molding compound 710 and on shield lidmounting surfaces 160. The conductivity of electrically conductive ink902 is selected to give appropriate shielding effectiveness. In oneembodiment, a screen print process is used to apply electricallyconductive ink 902. A post cure process may be used to cure/dryelectrically conductive ink 902.

Assembly 500 of FIGS. 8, 9 is singulated, e.g., saw singulated, alongsingulation streets 504 thus completing fabrication of shielded packages100 (FIGS. 1 and 2), shielded packages 1000 (FIG. 10), respectively.Interconnection balls are populated before or after singulation ofassembly 500.

Although the fabrication of a plurality of shielded packagessimultaneously is discussed above, in light of this disclosure, those ofskill in the art will understand that shielded packages can be formedindividually in a similar manner if desired. Illustratively, shieldedpackages are SiP RF modules or a laminate based overmolded packagehaving EMI shielding protection or to prevent RF emissions.

FIG. 10 is a cross-sectional view of a shielded package 1000 inaccordance with another embodiment of the present invention. Shieldedpackage 1000 of FIG. 10 is similar to shielded package 100 of FIG. 1 andonly the significant differences between shielded packages 100 and 1000are discussed below.

Shielded package 1000 includes a shield assembly 1040, which functionssimilarly to shield assembly 140 of shielded package 100. In thisembodiment, shield assembly 1040 includes shield fence 142 andelectrically conductive ink 902. Electrically conductive ink 902 is ashield lid for shield assembly 1040.

Electrically conductive ink 902 is a planar lid corresponding closely inshape to outer periphery 158 of shield lid mounting ring 150 of shieldfence 142. Electrically conductive ink 902 is in direct contact with,and thus electrically coupled to, shield lid mounting ring 150 of shieldfence 142. More particularly, electrically conductive ink 902 is indirect contact with, and thus electrically coupled to, shield lidmounting surface 160 of shield lid mounting ring 150.

The drawings and the forgoing description gave examples of the presentinvention. The scope of the present invention, however, is by no meanslimited by these specific examples. Numerous variations, whetherexplicitly given in the specification or not, such as differences instructure, dimension, and use of material, are possible. The scope ofthe invention is at least as broad as given by the following claims.

1. A structure comprising: a substrate comprising a first surface; aland and a plurality of traces on the first surface; an electroniccomponent coupled to the first surface; an encapsulant enclosing thefirst surface and the electronic component; and a shield lidelectrically coupled to the land through an electrically conductiveshield fence and mechanically coupled via the encapsulant through theshield fence, the shield lid comprising a cured electrically conductiveink in direct contact with a mounting ring of the shield fence and afirst surface of the encapsulant, and wherein the electronic componentcomprises a plurality of bond pads, the structure further comprisingbumps enclosed by an underfill material coupling the bond pads to thetraces on the first surface of the substrate.
 2. The structure of claim1 wherein the shield lid is electrically coupled to the land by anelectrically conductive material extending through the encapsulant. 3.The structure of claim 2 wherein the electrically conductive materialcomprises copper.
 4. The structure of claim 2 wherein the electricallyconductive material comprises solder.
 5. The structure of claim 4wherein the solder is on the land.
 6. The structure of claim 5 whereinthe electrically conductive material further comprises copper extendingbetween the solder and the shield lid.
 7. The structure of claim 2wherein the electrically conductive material comprises posts.
 8. Thestructure of claim 1 wherein the substrate further comprises a secondsurface, a trace on the second surface of the substrate being coupled tothe land.
 9. The structure of claim 1 further comprising a ground ringcomprising the land.
 10. A structure comprising: a substrate comprisinga first surface; a land and a plurality of traces on the first surface;an electronic component coupled to the first surface; an encapsulantenclosing the first surface and the electronic component; and a curedelectrically conductive coating formed on and in direct contact with afirst surface of the encapsulant and coupled to the land through anelectrically conductive shield fence and mechanically coupled via theencapsulant through the shield fence, the electrically conductivecoating being in direct contact with a mounting ring of the shieldfence, and wherein the electronic component comprises a plurality ofbond pads, the structure further comprising bumps enclosed by anunderfill material coupling the bond pads to the traces on the firstsurface of the substrate.
 11. A structure comprising: a substratecomprising a first surface; a land and a plurality of traces on thefirst surface; an electronic component coupled to the first surface; anencapsulant enclosing the first surface and the electronic component;and a cured electrically conductive ink in direct contact with amounting ring of a shield fence comprising an electrically conductivematerial, the electrically conductive ink being electrically coupled tothe land through the shield fence and mechanically coupled via theencapsulant by the electrically conductive material, the electricallyconductive ink in direct contact with a first surface of theencapsulant, and wherein the electronic component comprises a pluralityof bond pads, the structure further comprising bumps enclosed by anunderfill material coupling the bond pads to the traces on the firstsurface of the substrate.
 12. The structure of claim 11 wherein theelectronic component comprises a semiconductor device.
 13. The structureof claim 11 wherein the electronic component comprises a passive device.